Question about Barrel Threading

[Liljoebrshooter]

This is how I do it.
Joe Hynes

 

[Bamban]

In conjunction with the outboard spider, my front spider with finger clamps and ball bearings allows the barrel to gimbal.

To dial in the bore I use Deltronics pins. Once the dialed in I drill short of the shoulder, indicate the throat area with long reach interapid, once satisfied with throat running true, I followed with taper boring to within a few thou of the body and short of the shoulder. Taper boring ensures the hole is running true to the bore, final step is finish reaming to headspace. The finish reamer will follow the tapered hole with no runout.

Verify the runout at any place in the chamber and the leade angle.

Another verification whether the tenon thread is running true to everything else, put 5 tenths indicator on the thread and set the lathe for threading to the TPI, turn the lathe on and watch the indicator for any runout?

The last question how tight or loose do you cut the tenon thread??

Check out the pdf file, it is a compilation of chambering discussions, good read

 

[Liljoebrshooter]

That's almost the exact same way I chamber.
Joe Hynes

 

[Bamban]

That's almost the exact same way I chamber.
Joe Hynes

Joe,

A retired benchrest gunsmith tutored me on chambering barrels, it takes a little bit more time compared to plunging in with piloted reamer, but I truly believe it is worth the extra steps.

What I found even when the threads are running true, as well as the chamber, and the tenon shoulder square, when I screw on barrel extensions on AR barrels, the OD on some of the barrel extensions showed as much as 0.005 runout.

 

[Bobby Bailey]

@Bamban
That's pretty much our method.